Summary

Izuku Midoriya always wanted to be a hero. That dream was cut short at the age of 12 when he died of leukemia.

Two years later, being a ghost is getting kind of old. There's only so much to do when you're legally dead. But when Izuku finally meets All Might and his best friend gets accepted to the top hero school in the country, things get a lot more interesting.

Or

Izuku is a ghost who causes trouble for Bakugo, All Might, and all of Class 1-A.